smell

As a rugby player, Edward Baker was used to getting pummeled to the ground and knocked around in every which way imaginable.
He broke his nose over and over again and eventually lost his ability to pick up a scent.
But then this happened.
During a recent match, he got kicked in the face, and the accident allowed him to smell again for the first time in 20 years.
"I had an operation last year where they drilled into my nose to make me breathe better through it, but it didn't work." he said. "So where the surgeons failed this bloke's size 12 boot worked."
And just in time too.
Baker recognized the smell of gas near a school a few days later, and reported the leak to authorities, preventing a potential disaster.
Dean Martin said it best:

Many of us remember the dangerously delicious Mr. Sketch markers that had a pleasant aroma associated with each color that left us coloring our nostrils more than our paper. Tommy Edison, a blind YouTuber has declided to do his best in guessing the color of each based on smell only. Being born blind his understanding of colors is only based on what he's been told, so the results are rather impressive.